Touch panel and touch-panel-integrated organic light-emitting display device having touch electrodes with floating units

ABSTRACT

Disclosed herein are a touch panel and a touch-panel-integrated organic light-emitting display device that are capable of solving a retransmission problem while exhibiting excellent luminance and color viewing angle characteristics. The touch panel includes a plurality of first and second electrodes disposed on a substrate so as to intersect each other. Each first electrode includes a first touch electrode, the first touch electrode including a first metal mesh pattern having a lattice structure formed by a plurality of first and second line electrodes intersecting each other and a first floating unit disposed in the central part of the first metal mesh pattern, the first floating unit being electrically isolated from the first metal mesh pattern, the first floating unit being made of a transparent conductive material. Each second electrode includes a second touch electrode, the second touch electrode including a second metal mesh pattern formed by a plurality of third and fourth line electrodes intersecting each other in a lattice structure and a second floating unit disposed in the central part of the second metal mesh pattern, the second floating unit being electrically isolated from the second metal mesh pattern, the second floating unit being made of a transparent conductive material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of Republic of Korea PatentApplication No. 10-2016-0112212, filed on Aug. 31, 2016, which is herebyincorporated by reference in its entirety.

BACKGROUND

Field of Technology

The present disclosure relates to a touch panel and atouch-panel-integrated organic light-emitting display device, and moreparticularly to a touch panel that reduces a retransmission phenomenonand has high luminance and a wide viewing angle when applied to adisplay device, and a touch-panel-integrated organic light-emittingdisplay device.

Discussion of the Related Art

Image display devices, which are a core technology in the informationcommunication age, for displaying various kinds of information on ascreen, have been developed such that the image display devices arethinner, lighter, and portable, and exhibit high performance. Inaddition, organic light-emitting display devices, which control theamount of light that is emitted from an organic light-emitting layer todisplay an image, have been highlighted as flat panel display devices,which have lower weight and volume than cathode ray tubes (CRT).

Using a self-emitting organic light-emitting device, an organiclight-emitting display device does not need an additional light source,and may be realized as an ultra-thin display device. In recent years,therefore, research has been actively conducted into an in-cell touchtype touch-panel-integrated display device, which uses an organiclight-emitting device and includes a touch electrode array in alight-emitting cell.

An in-cell touch type touch panel includes a first touch electrodedisposed in a first direction and a second touch electrode disposed in asecond direction so as to intersect the first touch electrode. The firstand second touch electrodes are electrically isolated from each other.The touch panel senses a touch input by sensing a change of mutualcapacitance between the first and second touch electrodes when an objecthaving static electricity comes into contact with the touch panel.

As the thickness of the touch panel is reduced, the thickness of a coverpart that covers the upper surface of the touch panel may also bereduced. As a result, the distance between the first and second touchelectrodes and a user's finger is reduced. At this time, parasiticcapacitance between the first and second touch electrodes and the user'sfinger is increased. A retransmission phenomenon in which an unintendedtouch signal is generated due to such parasitic capacitance occurs, withthe result that touch sensitivity is lowered and malfunctions arecaused.

Meanwhile, research has been actively conducted into the application ofa metal mesh pattern exhibiting high flexibility and low resistance to atouch electrode in manufacturing an organic light-emitting displaydevice having a flexible in-cell touch structure. Since such a metalmesh pattern exhibits higher reflexibility than a transparent conductivematerial, however, the metal mesh pattern is easily visible to theoutside, with the result that the overall luminance of the organiclight-emitting display device is reduced. In order to solve thisproblem, there has been proposed a method of aligning the metal meshpattern with a bank, which is a non-emitting region. However, the metalmesh pattern may be misaligned with the display panel. In addition, evenwhen the metal mesh pattern is accurately aligned with the displaypanel, the metal mesh pattern is visible when the viewing angle isincreased. Consequently, it is difficult to secure excellent colorviewing angle characteristics of the organic light-emitting displaydevice.

SUMMARY

Accordingly, the present disclosure is directed to a touch panel and atouch-panel-integrated organic light-emitting display device thatsubstantially obviate one or more problems due to limitations anddisadvantages of the related art.

An object of the present disclosure is to provide a touch panel and atouch-panel-integrated organic light-emitting display device that arecapable of solving a retransmission problem while exhibiting excellentluminance and color viewing angle characteristics.

Additional advantages, objects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, atouch panel includes a plurality of first and second electrodes disposedon a substrate so as to intersect each other.

Each first electrode may include a first touch electrode, the firsttouch electrode including a first metal mesh pattern having a latticestructure formed by a plurality of first and second line electrodesintersecting each other and a first floating unit disposed in thecentral part of the first metal mesh pattern, the first floating unitbeing electrically isolated from the first metal mesh pattern, the firstfloating unit being made of a transparent conductive material.

Each second electrode may include a second touch electrode, the secondtouch electrode including a second metal mesh pattern formed by aplurality of third and fourth line electrodes intersecting each other ina lattice structure and a second floating unit disposed in the centralpart of the second metal mesh pattern, the second floating unit beingelectrically isolated from the second metal mesh pattern, the secondfloating unit being made of a transparent conductive material.

First touch electrodes adjacent to each other in the first direction maybe connected to each other via a bridge, and second touch electrodesadjacent to each other in the second direction may be connected to eachother via a connection mesh pattern.

The first and second floating units may be made of a material differentfrom that of the first and second metal mesh pattern. For example, eachof the first and second floating units may include transparentconductive patterns arranged while intersecting in the third and fourthdirections. A third segment electrode may be further provided betweenthe transparent conductive patterns. The third segment electrode may beintegrally formed with the transparent conductive patterns.

The touch panel according to the present invention may further include afirst segment electrode disposed in a contact fashion at theintersection of the first and second line electrodes and a secondsegment electrode disposed in a contact fashion at the intersection ofthe third and fourth line electrodes. Each of the first and secondsegment electrodes may be made of a transparent conductive material.

The touch panel may further include an interlayer dielectric filmdisposed to cover the first and second electrodes. The interlayerdielectric film may be provided with a plurality of contact holes,through which a portion of the edge region of the first metal meshpattern is exposed. The bridge may electrically connect two first metalmesh patterns adjacent to each other in the first direction through thecontact holes.

The bridge may be formed so as to overlap the connection mesh patternand the second metal mesh pattern.

Meanwhile, a fourth segment electrode may be further provided on theconnection mesh pattern.

In addition, the first metal mesh pattern may further include at leastone protrusion protruding from a region thereof adjacent to the secondmetal mesh pattern toward the second metal mesh pattern, the protrusionhaving an intersection of the first and second line electrodes. A fifthsegment electrode may be further provided in a contact fashion at theintersection of the protrusions.

In addition, the touch panel may further include at least one floatingsegment electrode disposed at the interface between the first and secondmetal mesh patterns, the floating segment electrode being configured toelectrically float, the floating segment electrode being made of atransparent conductive material.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a schematic plan view showing a display device including atouch panel according to one embodiment of the present disclosure;

FIG. 2 is a schematic sectional view taken along line I-I′ of FIG. 1according to one embodiment of the present disclosure;

FIG. 3 is a detailed view showing part A of FIG. 1, illustrating theshape and connection relationship of first and second touch electrodesaccording to one embodiment of the present disclosure;

FIG. 4 is an enlarged plan view showing region B of FIG. 3, illustratingthe detailed shape of floating units according to one embodiment of thepresent disclosure;

FIG. 5 is a sectional view taken along line x-x′ of FIG. 4, illustratinga touch electrode array according to one embodiment of the presentdisclosure;

FIGS. 6A and 6B are enlarged plan views showing region C of FIG. 3,illustrating the connection structure of a bridge and a connection meshpattern according to one embodiment of the present disclosure;

FIG. 7 is a sectional view of a touch electrode array taken along liney-y′ of FIG. 6 according to one embodiment of the present disclosure;

FIG. 8 is an enlarged plan view region D of FIG. 3, illustrating theinterface between a first touch electrode and a second touch electrodeaccording to one embodiment of the present disclosure; and

FIG. 9A is a graph showing the luminance and color viewing anglecharacteristics of an organic light-emitting display device to which aconventional touch panel is applied, and FIG. 9B is a graph showing theluminance and color viewing angle characteristics of an organiclight-emitting display device to which a touch panel according to thepresent invention is applied.

DETAILED DESCRIPTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts. In thefollowing description of the present invention, a detailed descriptionof known functions and configurations incorporated herein will beomitted when it may obscure the subject matter of the present invention.In addition, the terms used in the following description are selected inconsideration of ease of preparation of the specification, and may bedifferent from the names of parts constituting an actual product.

It will be understood that when an element is referred to as being “on”another element, it may be directly on the element, or one or moreintervening layers or elements may also be present therebetween. Incontrast, it will be understood that when an element is referred to as“contacting” another element, no intervening elements or layers arepresent therebetween.

The size and thickness of each element shown in the drawings are givenmerely for the convenience of description, and the present invention isnot limited thereto.

Hereinafter, a display device including a touch panel according to thepresent invention will be described with reference to the accompanyingdrawings.

FIG. 1 is a schematic plan view showing a display device including atouch panel according to the present disclosure.

The touch panel according to the present disclosure includes a pluralityof first electrodes 101 arranged on a substrate 1000 in the firstdirection and a plurality of second electrodes 102 arranged in thesecond direction, which intersects the first direction. In thisembodiment, the first direction is illustrated as being the horizontaldirection, and the second direction is illustrated as being the verticaldirection. However, the present invention is not limited thereto.

The first electrodes 101 include first touch electrodes 1011continuously arranged in the first direction. Adjacent ones of the firsttouch electrodes 1011 in the first direction are connected to each othervia bridges 912. In addition, the second electrodes 102 include secondtouch electrodes 1021 and connection mesh patterns 1027 continuouslyarranged in the second direction. The first electrodes 101 including thefirst touch electrodes 1011 may function as touch electrodes forapplying a touch signal, and the second electrodes 102 including thesecond touch electrodes 1021 may function as sensing electrodes forsensing the touch signal. However, the present invention is not limitedthereto.

The first and second touch electrodes 1011 and 1021 and the connectionrelationship therebetween will be described below in detail.

The first electrodes 101 are connected to a pad electrode 110 of a touchpad unit 2350 via first routing lines 111 a, and the second electrodes102 are connected to the pad electrode 110 of the touch pad unit 2350via second routing lines 111 b. In this embodiment, a pair of firstelectrodes 101 adjacent to each other in the vertical direction isconnected in parallel to one of the first routing lines 111 a so as tobe commonly connected to the pad electrode 110, and a pair of secondelectrodes 102 adjacent to each other in the horizontal direction isconnected in parallel to one of the second routing lines 111 b so as tobe commonly connected to the pad electrode 110. However, the presentinvention is not limited thereto. In the case in which the first andsecond electrodes 101 and 102 are connected to the pad electrode 110 inpairs, as described above, a pair of first touch electrodes 1011 and apair of second touch electrodes 1021 disposed at the intersection withthe pair of first touch electrodes 1011 is driven as a unit sensor U forsensing one set of touch coordinates.

FIG. 2 is a schematic sectional view taken along line I-I′ of FIG. 1.

The display device according to the present disclosure is configured tohave an in-cell structure in which a touch electrode array 230 isrealized in a display panel. In this embodiment, an organiclight-emitting display device having an in-cell structure is describedby way of example. However, the present invention is not limitedthereto. The display device according to the present disclosure isconfigured such that a first substrate 120, a first buffer layer 130, athin film transistor array 140, and an organic light-emitting array 150are sequentially disposed on the substrate 1000 and such that apassivation layer 160 is provided to cover the organic light-emittingarray 150. A second substrate 210, a second buffer layer 220, and atouch electrode array 230 are disposed inside a cover glass 3000. Thetouch electrode array 230 is laminated to the passivation layer 160,which is disposed on the organic light-emitting array 150, via a bondinglayer 400 so as to be opposite the organic light-emitting array 150.

Each of the first buffer layer 130 and the second buffer layer 220includes an active region and a dead region. The touch electrode array230, the organic light-emitting array 150, and the thin film transistorsin the thin film transistor array 140, excluding a pad unit, are formedin the active region. The touch pad unit and the pad unit of the thinfilm transistor array are formed in a portion of the dead region.

The first and second substrates 120 and 210 function to prevent damageto the arrays therein during a laser-application or etching process.According to circumstances, the substrate 1000 and the cover glass 3000are removed, and the first and second substrates 120 and 210 function toprotect the display device from the outside. Each of the first andsecond substrates 120 and 210 may be made of a polymer material, such aspolyimide or photoacryl.

Each of the first buffer layer 130 and the second buffer layer 220 isformed by continuously stacking the same kind of inorganic films, suchas oxide films (SiO₂) or nitride films (SiN_(x)), or by alternatelystacking different kinds of inorganic films. Each of the first bufferlayer 130 and the second buffer layer 220 functions as a barrier forpreventing moisture or external air from permeating into the organiclight-emitting array 150 in a subsequent process of laminating an uppersubstrate to a lower substrate.

The touch electrode array 230 and the touch pad unit 2350 are formed inthe same surface of the second buffer layer 220. The touch pad unit 2350is connected to a pad unit (not shown) of the thin film transistor array140 via a seal 450 including a conductive ball 455 during an upper andlower laminating process using the bonding layer 400. The bonding layer400 has a permeation prevention function. In addition, the bonding layer400 directly contacts the passivation layer 160, which covers theorganic light-emitting array 150. Consequently, the bonding layer 400functions to more securely prevent external air and moisture frompermeating into the organic light-emitting array 150, in addition to thefunction of the passivation layer 160.

The thin film transistor array 140, including the pad unit, is formedsuch that one side thereof protrudes further than the touch electrodearray 230. The reason for this is that a drive integrated circuit (IC)(not shown) for transmitting a signal for simultaneously driving thetouch electrode array, the thin film transistor array, and the organiclight-emitting array is provided at the protruding portion thereof.Although not shown, a thin film transistor array driving pad and dummypads include a plurality of dummy electrodes, which are connected to thedrive IC via wires. After the glass is removed, the drive IC isconnected to a flexible printed circuit board (FPCB) by bonding so as tobe controlled by a micro control unit (MCU) (not shown) and a timingcontroller (not shown) provided at the FPCB. The dummy pads are formedin the portion of the dead region outside the active region thatcorresponds to the touch pad unit on the same layer as metalconstituting a gate line or a data line.

A drive circuit may be mounted on the flexible printed circuit board oran anisotropic conductive film (ACF) using a chip-on-film (COF) method.

Although not shown, the thin film transistor array driving pad and thedummy pads are connected to each other via wires (not shown) formed onthe flexible printed circuit board or the lower substrate 1000. Inaddition, the flexible printed circuit board may be further providedwith a controller (not shown) for controlling the drive circuit.

The dummy pads are formed in the portion of the dead region outside theactive region that corresponds to the touch pad unit on the same layeras the metal constituting the gate line or the data line.

FIG. 3 is a detailed view showing part A of FIG. 1, illustrating theshape and connection relationship of the first and second touchelectrodes 1011 and 1021.

The first touch electrode 1011 according to the present disclosureincludes first metal mesh patterns 1012 a and 1012 b having a latticestructure formed by a plurality of first line electrodes 1031 and secondline electrodes 1032 intersecting in the third and fourth directions andfirst floating units 1014 a and 1014 b disposed in the central parts ofthe first metal mesh patterns 1012 a and 1012 b so as to be electricallyisolated from the first metal mesh patterns 1012 a and 1012 b. The firstfloating units 1014 a and 1014 b may be made of a material differentfrom that of the first metal mesh patterns 1012 a and 1012 b. Forexample, the first floating units 1014 a and 1014 b may be made of atransparent conductive material, such as indium tin oxide (ITO), indiumzinc oxide (IZO), indium gallium zinc oxide (IGZO), or (ZnO). However,the present invention is not limited thereto.

The first metal mesh pattern 1012 a, which is disposed on one side, andthe first metal mesh pattern 1012 b, which is disposed on the otherside, adjacent thereto in the first direction are electrically connectedto each other via a bridge 912.

First segment electrodes 1013 a and 1013 b may be further provided in acontact fashion at the intersection of the first and second lineelectrodes 1031 and 1032 in the third and fourth directions. The firstsegment electrodes 1013 a and 1013 b may be omitted depending on thedesign.

The second touch electrode 1021 according to the present disclosureincludes second metal mesh patterns 1022 a and 1022 b having a latticestructure formed by a plurality of third line electrodes 1033 and fourthline electrodes 1034 intersecting in the third and fourth directions andsecond floating units 1024 a and 1024 b disposed in the central parts ofthe second metal mesh patterns 1022 a and 1022 b so as to beelectrically isolated from the second metal mesh patterns 1022 a and1022 b. Like the first floating units 1014 a and 1014 b, the secondfloating units 1024 a and 1024 b may be made of a material differentfrom that of the second metal mesh patterns 1022 a and 1022 b. Forexample, the second floating units 1024 a and 1024 b may be made of atransparent conductive material, such as ITO, IZO, IGZO, or ZnO.However, the present invention is not limited thereto.

The first touch electrode 1011 and the second touch electrode 1021 ofthe touch electrode array 230 according to the embodiment of the presentdisclosure are formed on the same layer so as to be electricallyisolated from each other. However, the present invention is not limitedthereto.

In this embodiment, the third and fourth directions are diagonaldirections. However, the present invention is not limited thereto.

The second metal mesh pattern 1022 a, which is disposed on one side, andthe second metal mesh pattern 1022 b, which is disposed on the otherside, adjacent thereto in the second direction are electricallyconnected to each other via a connection mesh pattern, a description ofwhich will follow.

Second segment electrodes 1023 a and 1023 b may be further provided in acontact fashion at the intersection of the second metal mesh patterns1022 a and 1022 b in the first and second directions. The second segmentelectrodes 1023 a and 1023 b may also be omitted depending on thedesign.

Each of the first and second touch electrodes 1011 and 1021 according tothe embodiment of the present disclosure has a diamond shape. Each ofthe first and second metal mesh patterns 1012 and 1022 and the first andsecond floating units 1014 and 1024 also has a diamond shape. Thediamond shape may be changed depending on the structure of each pixel ofthe display panel. When each pixel of the display panel has a diamondshape, each of the first and second touch electrodes 1011 and 1021 andthe first and second metal mesh patterns 1012 and 1022 may be formed soas to have a diamond shape. In addition, each of the first and secondsegment electrodes 1013 a, 1013 b, 1023 a, and 1023 b that contact theintersection of the first and second metal mesh patterns 1012 and 1022may also have a diamond shape. Since each of the elements constitutingthe first and second touch electrodes 1011 and 1021, including the firstand second metal mesh patterns 1012 and 1022, has a diamond shape, it ispossible to prevent the metal mesh patterns from being visible. Thefirst and second metal mesh patterns 1012 and 1022 do not overlap theopening in each pixel but are disposed so as to overlap a non-displayregion or a black matrix of each pixel, thereby minimizing thevisibility of the metal mesh patterns.

Nevertheless, the first and second metal mesh patterns 1012 and 1022 maybe visible to a viewer depending on the viewing angle of the viewer atan arbitrary viewing position. As a result, the first and second metalmesh patterns 1012 and 1022 are visible at a viewing angle equal to orgreater than a predetermined level, whereby a luminance viewing angleand a color viewing angle are reduced. In the embodiment of the presentinvention, each of the first and second floating units 1014 and 1024 ismade of a transparent conductive material, whereby it is possible tominimizing the visibility of the first and second metal mesh patterns1012 and 1022 even when the viewing angle is changed.

Meanwhile, the touch panel according to the embodiment of the presentinvention includes first floating units 1014 a and 1014 b electricallyisolated from the first touch electrode 1011 and second floating units1024 a and 1024 b electrically isolated from the second touch electrode1021. The first floating units 1014 a and 1014 b reduce the effectiveelectrode area of the first touch electrode 1011, thereby reducingparasitic capacitance between a finger and the first touch electrode1011. In addition, the second floating units 1024 a and 1024 b reducethe effective electrode area of the second touch electrode 1021, therebyreducing parasitic capacitance between the finger and the second touchelectrode 1021. In the touch panel according to the embodiment of thepresent invention, therefore, a retransmission phenomenon may bereduced. The retransmission phenomenon may be further reduced as thearea of the floating units is increased. If the area of the floatingunits is too large, however, the area of the touch electrode isexcessively reduced, whereby touch sensitivity may be reduced. In thetouch panel according to the present invention, therefore, apredetermined area ratio of the floating units to the touch electrodesmay be set in order to maintain touch sensitivity while solving theproblem of retransmission. For example, the area ratio of the floatingunits relative to the touch electrodes 1011 and 1021 may be about 10 to65%.

In the touch panel according to the present invention, each of the firstand second metal mesh patterns 1012 and 1022 may be made of any oneselected from the group consisting of molybdenum, aluminum, chrome,gold, titanium, neodymium, and copper or an alloy thereof. Since theresistance of each of the first and second metal mesh patterns 1012 and1022 is low, the RC delay of the touch panel may be reduced.Furthermore, since a metal material exhibits high flexibility, the touchpanel according to the present invention may be applied to a flexibledisplay device.

In addition, when the touch panel according to the present inventionincludes the first and second segment electrodes 1013 and 1023 providedso as to contact the first and second metal mesh patterns 1012 and 1022,the effective capacitance of each of the first and second touchelectrodes 1011 and 1021 is increased, since each segment electrode hasa touch electrode surface, whereby the touch sensitivity of the touchpanel is improved.

FIG. 4 is an enlarged plan view showing region B of FIG. 3, illustratingthe detailed shape of the first and second floating units 1014 and 1024.The second floating unit 1024 b shown in FIG. 4 is provided in thesecond touch electrode 1021, and has the same structure as the floatingunits 1014 a and 1014 b provided in the first touch electrode 1011.

Referring to FIG. 4, the second floating unit 1024 b includestransparent conductive patterns 1025 arranged while intersecting in thefirst and second directions and a third segment electrode 1026 disposedin a contact state between the transparent conductive patterns 1025. Thethird segment electrode 1026 may be omitted depending on the design. Inthis case, the transparent conductive patterns 1025 intersect in thethird and fourth directions so as to be connected in a line, like theshape of the first and second line electrodes 1031 and 1032.

FIG. 5 is a sectional view taken along line x-x′ of FIG. 4, illustratingthe touch electrode array 230. The structure outside the buffer layer220 is omitted for the sake of convenience. In FIG. 5, only the secondfloating unit 1024 b of the second touch electrode 1021 is shown.However, the first floating units 1014 a and 1014 b of the first touchelectrode 1011 also have the same section.

Referring to FIG. 5, the second metal mesh pattern 1022 b is formed onthe buffer layer 220. The second segment electrode 1023 b is formed in acontact fashion at the intersection of the line electrodes of the secondmetal mesh pattern 1022 b. The transparent conductive pattern 1025 andthe third segment electrode 1026 of the second floating unit 1024 b areformed simultaneously when the second segment electrode 1023 b isformed. Since the transparent conductive pattern 1025 and the thirdsegment electrode 1026 are made of a transparent conductive material,such as ITO, IZO, IGZO, or ZnO, as described above, the transparentconductive pattern 1025 and the third segment electrode 1026 may beformed simultaneously.

An interlayer dielectric film 232 is formed on the entire surface of thebuffer layer 220, including the second metal mesh pattern 1022 b and thetransparent conductive pattern 1025 and the third segment electrode 1026of the second floating unit 1024 b. A passivation layer 233 is furtherformed on the interlayer dielectric film 232.

In the sectional view of FIG. 5, the buffer layer 220 is disposed on thelower side. When the touch electrode array 230 is actually laminated tothe organic light-emitting array 150 and the passivation layer 160,however, the structure of FIG. 5 is reversed. That is, the actualsection of the touch electrode array 230 taken along line x-x′ has ahorizontally-reversed form of the structure of FIG. 5.

As can be seen from FIGS. 4 and 5, the second floating unit 1024 b iselectrically isolated from the second metal mesh pattern 1022 b. Asdescribed above, therefore, the floating unit reduces the effective areaof the touch electrode, thereby reducing parasitic capacitance and theretransmission phenomenon afflicting the touch panel. In addition, sincethe floating unit is made of a transparent conductive material, thefloating unit is not visible at any viewing angle, whereby the colorviewing angle and the luminance viewing angle are increased further thanin the case in which the second floating unit 1024 b has a metal meshpattern.

FIGS. 6A and 6B are enlarged plan views showing region C of FIG. 3,illustrating the connection structure of the bridge 912 and theconnection mesh pattern 1027.

As shown in FIG. 6A, two first touch electrodes adjacent to each otherin the first direction are connected to each other via the bridge 912,and two second touch electrodes adjacent to each other in the seconddirection are connected to each other via the connection mesh pattern1027. The connection mesh pattern 1027 is formed on the same layer asthe first and second metal mesh patterns 1012 a, 1012 b, 1022 a, and1022 b, and is made of the same material as the first and second metalmesh patterns 1012 a, 1012 b, 1022 a, and 1022 b. The connection meshpattern 1027 extends from the third and fourth line electrodesconstituting the second metal mesh patterns 1022 a and 1022 b, and isformed in a shape in which two line electrodes intersect.

Consequently, the connection mesh pattern 1027 has a structure in whichtwo second metal mesh patterns 1022 a and 1022 b adjacent to each otherin the second direction are connected to each other using two lineelectrodes. However, the present invention is not limited thereto.

The bridge 912 is electrically isolated from the connection mesh pattern1027. As shown in FIG. 6B, the bridge 912 is formed so as to have ashape overlapping with the position of the connection mesh pattern 1027.Like the connection mesh pattern 1027, which is formed in a shape inwhich two line electrodes intersect, the bridge 912 may be formed so asto overlap the position of the two line electrodes constituting theconnection mesh pattern 1027. The bridge 912 is formed so as to overlapthe connection mesh pattern 1027 and to overlap even a portion of thesecond metal mesh patterns 1022 a and 1022 b and a portion of the firstmetal mesh patterns 1012 a and 1012 b. In addition, the bridge 912 isconnected to the first metal mesh patterns 1012 a and 1012 b via contactholes 1042. The bridge 912 may be made of the same material as the firstand second metal mesh patterns 1012 and 1022. A plurality of bridges 912may be provided.

This will be described in more detail with reference to FIG. 7.

FIG. 7 is a sectional view of the touch electrode array 230 taken alongline y-y′ of FIG. 6. The structure outside the buffer layer 220 isomitted for the sake of convenience.

Referring to FIG. 7, the first metal mesh patterns 1012 a and 1012 b,the second metal mesh patterns 1022 a and 1022 b, and the connectionmesh pattern 1027, which connects the second metal mesh patterns 1022 aand 1022 b, are formed on the buffer layer 220.

First segment electrodes 1013 a and 1013 b may be further provided so asto contact the first metal mesh patterns 1012 a and 1012 b. In addition,second segment electrodes 1023 a and 1023 b may be further provided soas to contact the second metal mesh patterns 1022 a and 1022 b, and afourth segment electrode 1028 may be further provided so as to contactthe connection mesh pattern 1027.

The interlayer dielectric film 232 is formed on the entire surface ofthe buffer layer 220, including the first and second metal mesh patterns1012 and 1022 and the first and second segment electrodes 1013 and 1023.The interlayer dielectric film 232 is provided with contact holes 1042,through which two adjacent first metal mesh patterns 1012 a and 1012 bare exposed. The bridge 912 is formed on the interlayer dielectric film232 so as to connect the two contact holes 1042.

The passivation layer 233 is disposed on the interlayer dielectric film232, including the bridge 912.

Actually, the touch electrode array 230 shown in FIG. 7 is laminated tothe organic light-emitting array 150 and the passivation layer 160 inthe reversed state. In actuality, therefore, the touch electrode array230 shown in FIG. 7 has the reverse form of the structure of FIG. 7.

As described above, the connection mesh pattern 1027 extends from thesecond metal mesh patterns 1022 a and 1022 b so as to have a shape inwhich two line electrodes intersect. That is, the connection meshpattern 1027 may also be linearly formed in a non-display region or ablack matrix region of each pixel so as not to overlap an opening regionof each pixel, thereby minimizing the visibility of the connection meshpattern 1027.

The bridge 912 also has a linear structure that is bent so as to overlapthe first and second metal mesh patterns and the connection meshpattern. Consequently, the bridge 912 is also formed in a non-displayregion or a black matrix region of each pixel so as not to overlap anopening region of each pixel, thereby minimizing the visibility of thebridge to a viewer.

Meanwhile, in FIGS. 6 and 7, the bridge 912 is shown as directlyconnecting the first metal mesh patterns. Alternatively, the bridge 912may be connected to the first segment electrodes on the first metal meshpatterns so as to electrically connect adjacent first touch electrodes.

FIG. 8 is an enlarged plan view region D of FIG. 3, illustrating theinterface between the first touch electrode 1011 and the second touchelectrode 1021.

As shown in FIG. 8, the first metal mesh pattern 1012 a includes atleast one protrusion 1042 protruding from the interface with the secondmetal mesh pattern 1022 a of the second touch electrode 1021 toward thesecond metal mesh pattern 1022 a and having an intersection of the firstand second line electrodes 1031 and 1032. A fifth segment electrode 1041may be further provided at the intersection of the protrusions 1042.

Two first touch electrodes 1011 adjacent to each other in the firstdirection are connected to each other via the bridge 912, and two secondtouch electrodes 1021 adjacent to each other in the second direction areconnected to each other via the connection mesh pattern 1027. At thistime, the second touch electrode 1021 of each second electrode 102 maybe further provided with a connection mesh pattern 1027 and a fourthsegment electrode 1028, whereby the second electrode 102 may have alarger effective area than the first electrode 101 in the designedstructure thereof. In this case, the effective area of the first touchelectrode 1011 constituting the first electrode 101 may be increased inorder to improve touch sensitivity.

In order to increase the effective area of the first touch electrode1011, the first metal mesh pattern 1012 a constituting the first touchelectrode 1011 includes a protrusion 1052 protruding toward the secondmetal mesh pattern 1022 a, and the second metal mesh pattern 1022 b isformed in a structure having therein a recess corresponding to theprotrusion 1052. That is, since the protrusion 1052 is included in thefirst metal mesh pattern 1012 a, the effective area of the firstelectrode 101 and the second electrode 102 is adjusted, whereby touchsensitivity is improved.

Meanwhile, in order to further improve luminance and viewing anglecharacteristics, at least one floating segment electrode 1051 may beprovided between the first metal mesh pattern 1012 a and the secondmetal mesh pattern 1022 a. The floating segment electrode 1051 may alsobe made of a transparent conductive material, such as ITO, IZO, IGZO, orZnO. The floating segment electrode 1051 may be provided at each firstmetal mesh pattern 1012 a. The floating segment electrode 1051 may beformed so as to include transparent conductive patterns and a segmentelectrode disposed therebetween, like the first and second floatingunits 1014 and 1024. However, the present invention is not limitedthereto.

In a display device to which the touch electrode array 230 is appliedthrough the floating segment electrodes 1051, further improvement ofluminance and viewing angle characteristics may be expected.

FIG. 9B is a graph showing the luminance and color viewing anglecharacteristics of an organic light-emitting display device to which aconventional touch panel is applied, and FIG. 9B is a graph showing theluminance and color viewing angle characteristics of an organiclight-emitting display device to which the touch panel according to thepresent invention is applied.

As shown in FIGS. 9A and 9B, it can be seen that the maximum luminanceof the organic light-emitting display device to which the touch panelaccording to the present invention is applied is higher than that of theorganic light-emitting display device to which the conventional touchpanel is applied, whereby a luminance decrease phenomenon due to anincrease in the viewing angle is also reduced.

In addition, it can be seen that a change of color coordinates ΔU′V′ dueto a change of the viewing angle of the organic light-emitting displaydevice to which the touch panel according to the present invention isapplied is greatly lower than that of the organic light-emitting displaydevice to which the conventional touch panel is applied.

Consequently, the organic light-emitting display device to which thetouch panel according to the present invention is applied has effects inthat luminance and the luminance viewing angle are increased and achange of color coordinates due to a change in the viewing angle isminimized, thereby improving color viewing angle characteristics,compared to the conventional art.

As is apparent from the above description, the present invention has thefollowing effects. When each pixel has a diamond shape and each of thefirst and second touch electrodes including the first and second metalmesh patterns has a diamond shape, it is possible to prevent the metalmesh patterns from being visible. The first and second metal meshpatterns do not overlap the opening in each pixel but are disposed so asto overlap the non-display region or the black matrix of each pixel,thereby minimizing visibility of the metal mesh patterns.

In the touch panel according to the present invention, each of the firstand second floating units is made of a transparent conductive material,whereby it is possible to minimize the visibility of the metal meshpatterns even when the viewing angle is changed.

Meanwhile, the touch panel according to the present invention includesfirst floating units electrically isolated from the first touchelectrode and second floating units electrically isolated from thesecond touch electrode. The first floating units reduce the effectiveelectrode area of the first touch electrode, thereby reducing parasiticcapacitance between a finger and the first touch electrode. In addition,the second floating units reduce the effective electrode area of thesecond touch electrode, thereby reducing parasitic capacitance betweenthe finger and the second touch electrode. In the touch panel accordingto the embodiment of the present invention, therefore, a retransmissionphenomenon may be reduced.

Since the resistance of each of the first and second metal mesh patternsis low, the RC delay of the touch panel may be reduced. Furthermore,since a metal material exhibits high flexibility, the touch panelaccording to the present invention may be applied to a flexible displaydevice.

In addition, when the touch panel according to the present inventionincludes segment electrodes provided so as to contact the first andsecond metal mesh patterns, the effective capacitance of each of thefirst and second touch electrodes is increased, since each segmentelectrode has a touch electrode surface, whereby the touch sensitivityof the touch panel is improved.

The connection mesh pattern extends from the second metal mesh patternsso as to have a shape in which two line electrodes intersect. That is,the connection mesh pattern may also be linearly formed in thenon-display region or the black matrix region of each pixel so as not tooverlap the opening region of each pixel, thereby minimizing thevisibility of the connection mesh pattern.

The bridge also has a linear structure that is bent so as to overlap thefirst and second metal mesh patterns and the connection mesh pattern.Consequently, the bridge is also formed in the non-display region or theblack matrix region of each pixel so as not to overlap the openingregion of each pixel, thereby minimizing the visibility of the bridge toa viewer.

In the touch panel according to the present invention, the protrusion isincluded in the first metal mesh pattern, whereby the effective area ofthe first and second electrodes is adjusted and touch sensitivity isimproved.

Additionally, in the touch panel according to the present invention, agreater improvement in luminance and viewing angle characteristics maybe expected owing to the floating segment electrodes.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A touch panel comprising: a plurality of firstelectrodes arranged on a substrate in a first direction; and a pluralityof second electrodes arranged in a second direction, which intersectsthe first direction, the second electrodes being electrically isolatedfrom the first electrodes, wherein each of the first electrodescomprises a first touch electrode, the first touch electrode comprisinga first metal mesh pattern having a lattice structure and a firstfloating unit disposed in a central part of the first metal meshpattern, the first floating unit being electrically isolated from thefirst metal mesh pattern, the first floating unit being made of amaterial different from a material of the first metal mesh pattern, thematerial of the first floating unit more transparent than the materialof the first metal mesh pattern; and each of the second electrodescomprises a second touch electrode, the second touch electrodecomprising a second metal mesh pattern having a lattice structure and asecond floating unit electrically isolated from the second metal meshpattern, the second floating unit being made of a material differentfrom a material of the second metal mesh pattern, the material of thesecond floating unit more transparent than the material of the secondmetal mesh pattern.
 2. The touch panel according to claim 1, wherein thefirst metal mesh pattern comprises a plurality of first line electrodesand second line electrodes, the first line electrodes and the secondline electrodes intersecting in third and fourth directions to form alattice structure, and the second metal mesh pattern comprises aplurality of third line electrodes and fourth line electrodes, the thirdline electrodes and the fourth line electrodes intersecting in the thirdand fourth directions to form a lattice structure.
 3. The touch panelaccording to claim 2 further comprising: a first segment electrodedisposed in a contact fashion at an intersection of the first and secondline electrodes; and a second segment electrode disposed in a contactfashion at an intersection of the third and fourth line electrodes. 4.The touch panel according to claim 3, wherein each of the first andsecond segment electrodes is made of a transparent conductive material.5. The touch panel according to claim 2, wherein the first metal meshpattern further comprises at least one protrusion protruding from aregion thereof adjacent to the second metal mesh pattern toward thesecond metal mesh pattern, the protrusion having an intersection of thefirst and second line electrodes.
 6. The touch panel according to claim5, further comprising a segment electrode disposed in a contact fashionat an intersection of the protrusions.
 7. The touch panel according toclaim 1, wherein each of the first electrodes comprise a bridge forconnecting the first touch electrodes adjacent to each other in thefirst direction, and each of the second electrodes comprise a connectionmesh pattern for connecting the second touch electrodes adjacent to eachother in the second direction.
 8. The touch panel according to claim 7,further comprising: an interlayer dielectric film disposed to cover thefirst and second electrodes, the interlayer dielectric film beingprovided with a plurality of contact holes, through which a portion ofan edge region of the first metal mesh pattern is exposed, wherein thebridge electrically connects two first metal mesh patterns adjacent toeach other in the first direction through the contact holes.
 9. Thetouch panel according to claim 8, wherein the bridge is disposed so asto overlap the second metal mesh pattern and the connection meshpattern.
 10. The touch panel according to claim 7, further comprising asegment electrode disposed on the connection mesh pattern.
 11. The touchpanel according to claim 1, wherein each of the first and secondfloating units comprises transparent conductive patterns arranged whileintersecting in the third and fourth directions.
 12. The touch panelaccording to claim 11, further comprising a segment electrode providedso as to contact the transparent conductive patterns.
 13. The touchpanel according to claim 12, wherein the segment electrode is integrallyformed with the transparent conductive patterns.
 14. The touch panelaccording to claim 1, further comprising at least one floating segmentelectrode disposed at an interface between the first and second metalmesh patterns, the floating segment electrode being configured toelectrically float and made of a transparent conductive material.
 15. Anorganic light-emitting display device comprising: a thin film transistorarray disposed on a substrate; an organic light-emitting array on thethin film transistor array; and the touch panel according to claim 1,the touch panel being laminated to the organic light-emitting array viaa bonding layer so as to be opposite the organic light-emitting array.16. A touch panel comprising: a plurality of first electrodes arrangedon a substrate in a first direction; and a plurality of secondelectrodes arranged in a second direction, which intersects the firstdirection, the second electrodes being electrically isolated from thefirst electrodes, wherein each of the first electrodes comprises a firsttouch electrode, the first touch electrode comprising a first metal meshpattern having a lattice structure and a first floating unit disposed ina central part of the first metal mesh pattern, the first floating unitbeing electrically isolated from the first metal mesh pattern, the firstfloating unit being made of a material different from a material of thefirst metal mesh pattern, wherein the first metal mesh pattern comprisesa plurality of first line electrodes and second line electrodes, thefirst line electrodes and the second line electrodes intersecting inthird and fourth directions to form a lattice structure; and each of thesecond electrodes comprises a second touch electrode, the second touchelectrode comprising a second metal mesh pattern having a latticestructure and a second floating unit electrically isolated from thesecond metal mesh pattern, the second floating unit being made of amaterial different from a material of the second metal mesh pattern,wherein the second metal mesh pattern comprises a plurality of thirdline electrodes and fourth line electrodes, the third line electrodesand the fourth line electrodes intersecting in the third and fourthdirections to form a lattice structure, wherein the first metal meshpattern further comprises at least one protrusion protruding from aregion thereof adjacent to the second metal mesh pattern toward thesecond metal mesh pattern, the protrusion having an intersection of thefirst and second line electrodes.
 17. The touch panel according to claim16, wherein each of the first electrodes comprise a bridge forconnecting the first touch electrodes adjacent to each other in thefirst direction, and each of the second electrodes comprise a connectionmesh pattern for connecting the second touch electrodes adjacent to eachother in the second direction.
 18. The touch panel according to claim16, wherein each of the first and second floating units comprisestransparent conductive patterns arranged while intersecting in the thirdand fourth directions.
 19. The touch panel according to claim 16,further comprising: a first segment electrode disposed in a contactfashion at an intersection of the first and second line electrodes; anda second segment electrode disposed in a contact fashion at anintersection of the third and fourth line electrodes.
 20. The touchpanel according to claim 19, wherein each of the first and secondsegment electrodes is made of a transparent conductive material.